Spuing fob chaiks



UNITED STATES PATENT OFFICE.

THOS. E. WARREN, OF TROY, NEW YORK.

SPRING FOR CHAIRS.

Specification of Letters Patent No.

To all whom t may concern:

Be it known that I, THos. E. WARREN, of Troy, in the county ofRensselaer and State of New York, have invented a new and Improved Modeof Constructing Springs, and that the following is a full, clear, andexact description of the principle or character which distinguishes itfrom all other things before known and of the usual manner of making,modifying, and using the same, reference being had to the accompanyiingdrawings, making a. part of this speciication.

Figure 1 is a longitudinal elevat-ion of the single spring. Fig. 2 alongitudinal section through the spring in a manner of the dotted line mm, of Fig. 1.

The nature of my invention consists in the using of the plates in areverse position from that adapted in ordinary elliptic springs, bywhich I am enabled to firmly aiiix both ends of each and every leaf ofwhich the spring is composed, and at the same time prevent them fromwearing by entirely separating them from each other except-ing wherethey may be fastened and not allowing any part of them to slide over anyrest or stationary part of the carriage, or other object they are usedto sustain.

The construction is as follows: For single springs of any number ofleaves, I form a block or box (a) into which the ends of the leaves canbe inserted, and securely fastened. The leaves (o) are of curveapproaching the astronomical sign M in form, the two ends being insertedone into the upper, and the other into the lower box, or otherfastenings at their bearings and two sets of said leaves form a singlespring; each of the leaves is constructed of such a curve as not totouch the next succeeding one except at their ends where they arefastened permanently by means of a wedge (0,) acted on by a screw boltthat passes through it, by

this arrangement it will be perceived that 6,740, dated September 25,1849.

there is no' rubbing of the surfaces of the leaves of the spring oneupon another. The leaves instead of straightening as in ellipticsprings, are made to contract, and act as braces to each other, by whichtheir strength is greatly increased, and is made to bear the weight withwhich they may be loaded, more steadily, without what is termed throwingit off by means of sudden jolts; in fact, this spring combines all theadvantages of the well known C spring and elliptic vspring without beingsubject to the defects of either, the leaves are nearly or quite of thesame thickness and breadth throughout their length and are thus lessliable to tire and require a less amount of metal to support a givenweight than any spring with which I am acquainted.

The double springs are composed of two sets of single ones, placed atright angles to each other,v and it is obvious that when only one or twoleaves are used, other modes of fastening their ends or bearing than thebox above described can be employed.

Having thus fully described the nature of my new and improved springwhat I claim therein as new and desire to secure by Letters Patent, is

The employment of two or more sets of bow shaped or other regular curvedleaves, substantially such as herein described, being made of metal ofthe same thickness and breadth throughout or nearly soand firmlyattached by their ends or bearings to the boxes, or other fixture bywhich they are held in place, each leaf composing said springs workingseparate from the others, as above specified, and firmly fastened attheir ends or bearings, as applied to chairs and other similar purposesas described and represented.

THOS. E. VARREN. lVitnesses:

E. L. BRUNDAGE, E. BELL.

